JPH0418015Y2 - - Google Patents

Description

[Detailed description of the invention] 1. Industrial application field This invention detects the pressure on the secondary side and changes the opening degree of the valve body using the energy of the fluid itself, so that the pressure on the secondary side is changed from the primary side pressure to a predetermined secondary side pressure. The present invention relates to a pressure reducing valve that automatically adjusts the pressure, and particularly relates to a pressure reducing valve that has a built-in drain discharge mechanism, that is, a steam trap, to prevent drain gas from flowing into the secondary side.

When steam is cooled, it becomes condensate (condensate), and especially in the early stages of ventilation, a large amount of condensate is generated because the piping system is at a low temperature, and the condensate flows into the pressure reducing valve together with the steam. This drainage causes vibrations in the pressure reducing valve due to hunting and chattering, which not only hinders its operation, but also causes water hammer in the piping system, damaging connected equipment, and corrosion of the parts that come into contact with the drain. This can lead to a shortened lifespan.

Furthermore, the drain after dissipating the latent heat for use in work is only sensible heat, and its enthalpy is small, so it must be removed before entering the secondary piping, that is, the steam equipment. As a result, equipment efficiency increases,
Leads to improved productivity.

2. Prior art Therefore, in the past, in order to solve the above problem,
No. 59-026527, a float type steam trap was provided at the bottom of the pressure reducing valve body, and condensate was discharged from the trap to the outside during the initial stage of ventilation and during operation.

3 Problems to be solved by the present invention Drain to be discharged has a saturation temperature, that is, sensible heat, corresponding to the primary pressure. Since the pressure on the secondary side is necessarily lower than that on the primary side, if saturated condensate at the primary pressure is flowed into the secondary pressure atmosphere, flash steam and secondary side pressure equal to the saturated temperature difference between the two will be generated. Becomes a pressure saturated drain. In other words, conventionally, flash steam that could be used for heat was also excluded.

The technical problem of the present invention is to flow the flash steam to the secondary side and remove the drain to the outside.

4 Technical means to solve the problem The technical means of the present invention taken to solve the above problem is to install a flush tank and a steam trap at the drain outlet of the pressure reducing valve that has a built-in steam trap. A pressure reducing valve device that connects the flash tank and the secondary side piping of the pressure reducing valve with a pressure equalizing pipe.

5. Function The flush tank has the same pressure as the secondary piping through a pressure equalizing pipe. Drain discharged from the pressure reducing valve once flows into the flash tank, where it becomes flash steam corresponding to the secondary side pressure and saturated drain. The flash steam flows through the pressure equalization pipe to the secondary piping and is used. The saturated condensate is discharged to the outside by a steam trap attached to the flash tank.

6 Effects of the invention Since the flashing steam that was conventionally discarded is reused, the amount of heat required for flashing from the primary pressure to the secondary pressure is saved. Therefore, the larger the pressure reduction ratio, the larger the flashing rate, and the more heat can be utilized.

7 Example An example showing a specific example of the above technical means will be described.

In the present invention, an external steam trap is attached to the drain outlet of a pilot operated steam pressure reducing valve, and the steam trap and the secondary side piping of the pressure reducing valve are connected by a pressure equalizing pipe. A detailed explanation will be given below.

First, the pressure reducing valve will be explained (see section A in FIG. 1).
The structure consists of a pressure reducing valve section 101, a steam/water separator section 102, and a drain valve section 103.

The main body 110 has an inlet 112, a valve port 114, and an outlet 1.
form 16. The inlet is connected to a high pressure fluid source on the primary side, and the outlet is connected to a low pressure region on the secondary side. The valve port is formed by a valve seat member.

The main valve body 118 is placed on the valve seat at the inlet side end of the valve port 114 and is elastically biased by a coil spring.

A piston 120 is slidably disposed within the cylinder 122, and the piston rod is brought into contact with the central protruding rod of the main valve body 118 through the valve port 114. The lower surface of the piston and the piston rod 12 are coaxially connected.
A pilot valve 126 is disposed in a primary pressure passage 124 that communicates the inlet 112 with the upper space of the piston 120, that is, the piston chamber. The diaphragm 128 is attached with its outer peripheral edge sandwiched between the flanges 130 and 132. The space below the diaphragm 128 communicates with the outlet 116 through a secondary pressure passage 134 .

The head end surface of the valve stem 136 of the pilot valve 126 abuts against the central lower surface of the diaphragm 128.

A pressure setting coil spring 140 is brought into contact with the upper surface of the diaphragm 128 via a spring seat 138. An adjustment screw 144 is threadedly attached to the main body 110.

Turning the adjusting screw 144 left and right changes the elastic force of the pressure setting spring 140 that pushes down the diaphragm 128. Using the elastic force of the pressure setting spring 140 as a reference value, the diaphragm 128 bends in response to the secondary pressure acting on its lower surface, displacing the valve stem 136 and opening and closing the pilot valve 126.
As a result, the primary side fluid pressure is introduced into the piston chamber, the piston 120 is driven, the main valve body 118 is displaced, and the fluid at the inlet 112 is transferred to the valve port 114.
through to outlet 116. This automatically operates so that the valve port 114 opens when the fluid pressure on the secondary side decreases and closes when it increases.

A cylindrical partition member 146 is provided below the valve port 114.
is attached to form an annular space 148 between it and the surrounding body 110, the upper part of which communicates with the inlet 112 through a cone-shaped screen 150,
The lower part communicates with the upper part of the drain valve chamber 152. Also,
The upper part of the drain valve chamber 152 communicates with the valve port 114 through the central opening of the partition member 146. Annular space 14
A swirl vane 154 consisting of an inclined wall is disposed at 8.

Therefore, when the valve port 114 opens and the fluid in the inlet 112 passes through the annular space 148, its direction is bent by the swirl vanes 154 and the fluid is swirled. The liquid is shaken out to the outside, hits the surrounding inner wall of the main body, and flows down into the drain valve chamber 152, while the light gas swirls around the center and flows from the central opening of the partition member 146 to the valve port 1.
14, through which it flows away to outlet 116.

A drain valve port 158 communicating with the drain port 156 is formed at the bottom of the drain valve chamber 152 . Covered with a float cover 162, a spherical valve float 160 is movably accommodated. A ventilation hole 164 is opened in the upper part of the float cover 162.

Therefore, the valve float 160 floats up and down with the water level in the drain valve chamber 152 to open and close the drain valve port 158, and automatically removes water accumulated in the drain valve chamber 152.

Next, we will explain the external steam trap.
(See part B in Figure 1) The valve casing members 10 and 11 are made by press-molding stainless steel thin plates. The shapes are symmetrical to each other,
It has an almost flat-bottomed cup shape with a 45-degree slope.

The inlet member 12 and the outlet member 13 are coaxially welded to the bottom surfaces of the valve casing members 10 and 11, and are mounted at a position offset from the inclined surface and to the left in FIG. Valve casing member 10 on the inlet side
A pressure equalizing pipe seat 30 is welded perpendicularly to the inclined surface of the pipe. The welding locations are 16, 17, and 32. Entrance 24
A female thread for piping is formed at the outlet 25 and the pressure equalization port 31. Inside the inlet side valve casing member 10,
A screen 28 having a substantially hemispherical shell shape is attached by spot welding at several locations. The screen 28 is made by press-molding a thin stainless steel plate with small holes drilled all over.

The partition member 20 is made by press-molding a thin stainless steel plate into a substantially hemispherical shell shape. The open end is cylindrical and has the same diameter as the open ends of the valve casings 11,12.

A valve seat member 21 having a valve port 27 formed therein is welded to the lower part of the partition member 20. (Place numbered 22). A float guide member 15 is attached to the valve seat member 21.
The float guide member 15 has two legs that are parallel to the axis of the valve port 27 and spaced apart from the axis by the radius of the float described below. One end of the U-shaped bimetal 29 is sandwiched and attached between the valve seat member 21 and the partition member 20.

The valve casing members 10 and 11 are welded to both sides of the cylindrical end of the partition member 20 (at locations 18 and 19), a passage 23 is formed in the partition member 20 and the valve casing member 11 on the outlet side, and the partition member 20 is welded to both sides of the cylindrical end. A valve chamber 26 is formed between the valve casing member 20 and the inlet side valve casing member 10. In this embodiment, the valve chamber also serves as a flush tank.

Reference numeral 14 is a spherical float made of a hollow stainless steel thin plate, and is accommodated in the valve chamber 26 in a free state.

The installation and piping methods for the pressure reducing valve and steam trap are as follows. Pressure reducing valve drain outlet 1
56 and the inlet 24 of the steam trap are connected with a pipe connecting material such as a nipple. Piping 34 connected to pressure equalization port 31 and piping 35 attached to secondary side piping 36
Connect with a union 33 or a pipe connection material such as a flange.

The operation is as follows. The drain discharged from the pressure reducing valve becomes flash steam in an amount corresponding to the pressure of the secondary piping in the valve chamber 26 of the steam trap and enters the secondary piping through the piping 34 and 35. Inside the valve chamber 26, steam is separated into the upper part and drain is collected in the lower part. As the drain water level rises, the float 14 becomes more buoyant and floats up to open the valve port 27.
Condensate flows through passage 23 and out of outlet 25. When the water level decreases due to discharge, the float 14 descends and closes the valve port 27 at the position on the float guide member 15, thereby stopping the drain from flowing out. This kind of operation is automatically repeated.

Condensate inside the pressure reducing valve must be removed quickly so that it does not flow into the secondary side, but in the external steam trap, it is preferable to increase the volume of the valve chamber 26 and store a large amount of condensate so that the condensate can be sufficiently flushed out. . For this purpose, a lever float type steam trap may be used instead of using a free float as in this embodiment.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a pressure reducing valve device according to an embodiment of the present invention. 10, 11... Valve casing member, 24... Inlet, 25... Outlet, 31... Pressure equalization port, 27... Valve port, 33... Union, 110... Main body, 112
...Inlet, 114...Valve port, 116...Outlet, 1
20...Piston, 126...Pilot valve.

Claims (1)

[Scope of utility model registration request] A pressure reducing valve device in which a flash tank and a steam trap are connected to the drain outlet of a pressure reducing valve with a built-in steam trap, and the flash tank and the secondary piping of the pressure reducing valve are connected with a pressure equalizing pipe.